What/is there a general rule as to who can enforce a covenant between land owners.

For example:

A owns 4 lots, two alongside the beach, two one block back. He sells the beachfront lots to B with a covenant banning 2 story buildings. A lives on one of the other lots, and sells the other one to C. Later, B begins to construct a monstrous beachfront 12 story building. Can C sue enforce the covenant?

Since this covenant benefits C, he should be able to enforce the covenant, provided:

1. The covenant was written down to satisfy Statute of Frauds2. A intended the covenant to pass to C in the transaction3. The covenant touches and concerns the land (which, would be your yes/no argument)4. C is in privity with A (generally, benefits just need to be same or less than conveyor's obligation, while burdens require privity of the entire interest)5. No notice is needed for benefits, but notice is required for burdens. Here, again, this is a benefit to C, so there is no notice needed.

Requirements are a bit different for equitable servitudes (lower burden of privity and notice), so make sure this truly is a covenant.